#include <REGX52.H>
void Delay1ms(unsigned int xms)		//@12.000MHz
{
	unsigned char i, j;
	while(xms--)
	{
		i = 2;
		j = 239;
		do
		{
			while (--j);
		} while (--i);
	}
	
}
void main()
{
	unsigned char lednum=0;
	while(1)
	{
		if(0==P3_1)
		{
			Delay1ms(20);
			while(0==P3_1);
			Delay1ms(20);
			P2=~lednum;
			lednum++;
		}
	}
}

